RESISTIVITY PRECURSORS AND SPREADING OF FAULT PRIOR TO ITS INSTABILITY

作     者：王新华 祁贵仲 赵玉林 WANG XINHUA QI GUIZHONG AND ZHAO YULIN (Institute of Geophysics, State Seismological Bureau, Beijing)

作者机构：Institute of Geophysics State Seismological Bureau Beijing 

出 版 物：《Science in China,Ser.B》 (中国科学B辑(英文版))

年 卷 期：1985年第28卷第4期

页      面：420-436页

核心收录：

学科分类：1002[医学-临床医学] 100214[医学-肿瘤学] 10[医学] 

主　　题：spreading blind propagating approximate volumetric instability formulae contour resistivity appearing 

摘      要：Based on fracture mechanics it has been found that earthquake precursors related to volumetric strain e are characterized by quadrants, blind zone and uneven propagation, and the approximate formulae for spreading range of precursor have been obtained. These results are coincident with the information of resistivity ρx observed before the Tangshan earthquake, and then mechanical explanations have been made for some precursors of ρx, such as precursors appearing concentratedly within the period of 1—2 years before the instability of the fault （i.e. subcritical period in which the fault spreads acceleratingly）. Before instability of the spreading of fault, the range of e=10-6 reaches about 150 km, its propagating velocity is about 100 km/yr, the amplification coefficient of ρx is about 104, etc. The half length of fault before instability is about 35km. It seems that in propagating process the spreading of the fault is delayed by barrier.